1. Field of the Invention
The present invention relates generally to a media data classification. More particularly, the present invention relates to an apparatus and a method for classifying IP Multimedia Subsystem (IMS)-based media data when a mobile communication system uses a data service.
2. Description of the Related Art
FIG. 1 illustrates a connection between a general Gateway GPRS Support Node (GGSN) and a Packet Data Protocol (PDP) context.
In a 3rd Generation Partnership Project (3GPP)-based IP Multimedia Subsystem (IMS) of FIG. 1, as generating a primary PDP context, the GGSN 120 determines whether to use a corresponding primary PDP context only for an IMS signaling or for general purposes by examining a Protocol Configuration Options (PCO) field in a message received from an IMS terminal 110.
The GGSN 120 of FIG. 1 can transmit signaling and data not only over the Internet but also over IMS networks. The GGSN 120 can have a plurality of primary/secondary PDP contexts with the terminal 110. The GGSN 120 can support up to eleven primary/secondary PDP contexts for a single terminal.
In an IMS based on the 3GPP Release 6, as generating a secondary PDP context, the IMS terminal 110 transmits a message including an authorization_token generated by a Policy Decision Function (PDF)/Policy and Charging Rules Function (PCRF) 142 to the GGSN 120. Hence, the GGSN 120 can acquire that the corresponding secondary PDP context contains the IMS-based media.
In an IMS based on the 3GPP Release 7, when the primary PDP context is generated, the GGSN 120 can determine whether not only the primary PDP context but also the following secondary PDP context are dedicated to the IMS by examining an IMS Access Point Name (APN) received from the terminal 110.
FIG. 2 illustrates a conventional PDP context generation dedicated to IMS signaling.
As generating a primary PDP context dedicated to IMS signaling (step 1), the GGSN 230 maps a secondary PDP context only to the IMS when the IMS APN is included. Herein, when the primary PDP context, which is not for a new IMS, is generated (step 11), an IP address should be allocated to the MS 210 using a general APN.
FIG. 3 illustrates a conventional PDP context generation (steps 1˜14) for the general-purpose signaling including the IMS APN.
As generating the general-purpose primary PDP context which includes IMS APN (step 1), non-IMS service can be provided through the primary PDP context.
However, specific contents service is not available using the secondary PDP context. That is, the secondary PDP context is used only for the IMS service.
FIG. 4 illustrates a conventional PDP context generation (steps 1˜8) of the general-purpose signaling without the IMS APN.
When a general-purpose primary PDP context (step 1) which includes no IMS APN is generated, the GGSN cannot determine whether a secondary PDP context to be generated is used for the IMS service or not.
As discussed above, to use a new non-IMS service after generating the primary PDP context dedicated to the IMS signaling, the terminal needs to generate a new general-purpose primary PDP context. For doing so, a new IP address on the primary PDP context basis should be allocated to the terminal.
The IMS structure based on the 3GPP Release 6 uses an authorization_token to determine whether the secondary PDP context is used for the IMS. In doing so, it is required that the PDF generate and transmit the authorization_token to the Proxy (P)-CSCF during a Session Initiation Protocol (SIP) signaling. Disadvantageously, this causes latency.
In the EMS based on the 3GPP Release 7, when the IMS terminal uses the IMS signaling and the non-IMS service by generating the general-purpose primary PDP context, the GGSN cannot determine whether the secondary PDP context to be generated includes IMS media data or non-IMS media data.
When the terminal performs an IMS service deregistration, the PDP context dedicated to the IMS is deleted. When the primary PDP context dedicated to the IMS signaling is generated, the PDP context is deleted. Yet, when the primary PDP context is defined for the general purposes, there is no method suggested for processing such a primary PDP context.
Accordingly, there is a need for an improved apparatus and method for classifying media data in a mobile communication system.